The present invention relates broadly to a filter apparatus, and in particular to a backlash filter apparatus for the removal of spurious electrical noise.
In the prior art, electrical filters are well known and find applications in almost all electrical communication and control systems. Radio and television receivers utilize filters to pass a particular selected channel and to reject all other channels. There have been narrow-band band-rejection filters that are used to reduce interference due to spurious electrical noise which may be internally generated by the electronic circuits themselves or external noise signals that have penetrated the unit. One of the more common usages of filter circuits is as a low-pass filter to act as a decoupling network between several amplifier circuits that share the same power supply. In the prior art there has been attempts to utilize conventional low pass filters to eliminate jitter from the output of a bang-bang control system which was being used to position a video camera. Thus, there exists a clear need to eliminate display jitter which was objectionable to operators; however, the use of conventional low pass filtering was found to be unsuitable due to system slew rate requirements. The present invention provides a filter apparatus that eliminates display jitter and compatible with system slew rate requirements.